In fungal naming, a synonym is another scientific name for the same taxon. Species Fungorum lists Copelandia cyanescens as a synonym of Panaeolus cyanescens (Species Fungorum). A basionym is the earlier, legitimate name whose epithet a new combination reuses (Madrid Code, Art. 6.10): Stropharia cubensis Earle (1906) is the basionym of Psilocybe cubensis (Species Fungorum).
Synonymy is a judgement, and it can change. Psilocybe quebecensis, named from Quebec material in 1967, is now treated as a synonym of the Mexican Psilocybe aztecorum by Index Fungorum (Index Fungorum). Another authority may disagree, so it is best to say which database a synonym comes from and when it was checked.
A synonym is different from a common name, a spelling variant or a misapplied name. Two names sharing an epithet, like Psilocybe cyanescens and Panaeolus cyanescens, are not synonyms at all. An old name in an old book usually means the same species under an earlier label, not a different mushroom.
Sources
- Species Fungorum: Panaeolus cyanescens synonymy
- Madrid Code (ICN, 2025), Art. 6.10
- Species Fungorum: Stropharia cubensis record
- Index Fungorum web service: Psilocybe quebecensis
Last checked .